1. Field of the Invention
The present invention relates to cartridges for storing ink. More particularly, this invention pertains to a reusable cartridge that is suitable for use with non-water soluble printer ink.
2. Description of the Prior Art
Inkjet technology provides a more-or-less ubiquitous alternative to other commonly employed technologies (e.g. laser) over a broad spectrum of document imprinting applications. Common and well-recognized applications of this technology include computer printers and facsimile machines. Inkjet printing advantageously produces documents that are not subject to the fading observed with other technologies such as laser printers.
Such technology involves the selective, patterned heating of ink contained within a cassette for controlled dispersion onto a sheet of paper. A representative cartridge for an inkjet printer is disclosed, for example, in U.S. Pat. No. 6,328,424 of Gary Allen Denton et al. titled “Inkjet Cartridge With Simultaneous Electrical and Fluid Connections”. Such patent teaches a refillable cartridge that includes a foam-filled ink reservoir. A filter of mesh-like composition is provided between the foam-filled reservoir and a standpipe that forms a lower reservoir. The filter eliminates air bubbles that would otherwise degrade the printing process. The ink moves from the foam-filled reservoir through the standpipe into a chamber or “lower reservoir” wherein it may be selectively heated by an arrangement of heaters to cause the ink to be selectively thinned to permit passage, by capillary action, to a paper surface.
Recycling of inkjet cartridges is complicated by the necessary presence of the mesh-like filter. This is especially the case in the event that the ink stored in the cartridge is oil-based. Commonly, such a filter is either glued or laser welded to the open top of the stand pipe and the empty cartridge must be recharged with ink without its removal and replacement as such a process would be difficult and prohibitively expensive. As a result, the filter, often clogged with particles of contaminants and dried ink, is generally the cause of the abysmally low rate of success (generally about 40 per cent) of conventional cartridge recycling processes.